Interpretive Summary: Lipase is one of the most important enzymes applied to the broad range of industrial application fields. Lipases with abnormal functionality such as thermo stability, alkaline, acidic, and cold-activity gain special attention because of their applicability in the restricted reaction conditions. In this study, sixteen yeast strains prescreened for lipase induction were investigated for their actual lipase production and a novel cold-active lipase produced from Pichia lynferdii Y-7723 was found. This study demonstrated that the cold activity of lipase Y-7723 at 10 deg C was the highest among the cold-active lipases reported so far.

Technical Abstract:
Lipase (triacylglycerol acylhydrolases, E.C. 3.1.1.3.) is one of the most important enzymes applied to the broad range of industrial application field. Especially, lipases with abnormal functionality such as thermo stability, alkaline, acidic, cold-activity gain special attention because of their applicability in the restricted reaction conditions. In this study, sixteen yeast strains prescreened for lipase induction were investigated for their actual lipase production and we found out a novel cold-active lipase produced from Pichia lynferdii Y-7723. Activity of lipase Y-7723 was retained by 74% and 70% at 20 deg C and 10 deg C, respectively, compared to the maximum value at 35 deg C. Based on optimization study, optimal lipase productivity was obtained at 96 hr incubation with 3% oil substrate in a medium composed of sucrose as a carbon source at pH 7.0. Among carbon sources tested, sucrose showed almost twice as high lipase production (184%) as control while cell growth was similar (105%). Yeast extract and ammonium salts were effective as an individual nitrogen source for lipase production. This study demonstrated that the cold-activity of lipase Y-7723 at 10 deg C was highest among the cold-active lipases reported so far.